Multichannel cannula and methods for using same

ABSTRACT

A method for delivering a substance to bone includes placing a stabilizing wire in a bone, creating a hole in the bone around the stabilizing wire, and providing a multichannel cannula. The multichannel cannula includes a first channel having an open proximal end and distal end, the first channel being configured to receive the stabilizing wire, and a second channel having an inlet portal and an exit portal that are in fluid communication. The cannula further includes a cap having a delivery port in fluid communication with the inlet portal and a channel for receiving the cannula therein, and a distal tip. The method further includes inserting the multichannel cannula into the hole in the bone such that the first channel receives the stabilizing wire, and delivering the substance into the bone by introducing the substance into the second channel such that the substance exits through the exit portal.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 14/081,784filed Nov. 15, 2013, which is a continuation-in-part of U.S. applicationSer. No. 13/679,312 filed Nov. 16, 2012, both of which are herebyincorporated by reference in their entireties.

BACKGROUND

The present invention relates generally to the field of devices andmethods for delivering substances to bone. More particularly, thepresent invention concerns devices and methods for delivering substancesto the interior of fractured or otherwise injured bones, especially tothe fracture interface. The present invention further relates to devicesand methods for removing material from the interior of a bone.

As techniques for delivering substances to bone progress, there remainsan imprecision during substance delivery prior to bone implantplacement. A bone implant may be a bone screw, nail, or other deviceimplanted into a bone to stabilize portions of a fractured bone. Atleast three techniques are currently available to deliver substances tobone. One technique involves delivering the substance into a drilledhole in a fractured bone without fracture stabilization. The lack offracture stabilization causes difficulties in delivering substances toan intended location using this technique. A second technique includesdrilling a separate hole in a bone for the substance to be deliveredafter implant placement. Drilling a separate hole causes additionaltrauma to the bone, and may also limit accessibility to the intendeddelivery location. In a third technique, the substance is deliveredthrough the implant. This technique requires the use of a fenestrated orslotted implant.

SUMMARY

The embodiments described herein allow delivery of a substance (e.g.,medication) to a fracture site after stabilization of the bone.Furthermore, the embodiments described herein allow delivery of asubstance to bone through the same hole that will receive the boneimplant, without requiring a separate hole to be drilled into the bone.The devices and methods described herein also allow material to beremoved from the interior of a bone.

One embodiment of the invention relates to a method for delivering asubstance to bone. The method includes placing a stabilizing wire in abone and creating a hole in the bone around the stabilizing wire. Amultichannel cannula is provided that includes a first channel having anopen proximal end and an open distal end, the first channel beingconfigured to receive the stabilizing wire. The multichannel cannulafurther includes a second channel having an inlet portal and an exitportal that are in fluid communication. The method further includesinserting the multichannel cannula into the hole in the bone such thatthe first channel receives the stabilizing wire, and delivering thesubstance into the bone by introducing the substance into the inletportal of the second channel such that the substance exits the secondchannel through the exit portal.

Another embodiment of the invention relates to a method for removingmaterial from a bone. The method includes placing a stabilizing wire ina bone and creating a hole in the bone around the stabilizing wire. Amultichannel cannula is provided that includes a first channel having anopen proximal end and an open distal end, the first channel beingconfigured to receive a stabilizing wire. The multichannel cannulafurther includes a second channel having an inlet portal and an exitportal that are in fluid communication. The method further includesinserting the multichannel cannula into the hole in the bone such thatthe first channel receives the stabilizing wire. The method furtherincludes coupling a suction device to the multichannel cannula, andremoving a material from an interior of the bone by activating thesuction device such that the material is drawn into the second channelthrough the exit portal of the second channel and the material exits thesecond channel through the inlet portal of the second channel.

Yet another embodiment of the invention relates to a multichannelcannula for delivering a substance to bone. The multichannel cannulaincludes a first channel having an open proximal end and an open distalend. The first channel is configured to receive a stabilizing wire. Themultichannel cannula further includes a second channel having an inletportal and an exit portal that are in fluid communication.

Alternative exemplary embodiments relate to other features andcombinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE FIGURES

The disclosure will become more fully understood from the followingdetailed description, taken in conjunction with the accompanyingfigures, wherein like reference numerals refer to like elements, inwhich:

FIG. 1 illustrates a bone with a stabilizing wire and a hole in the bonearound the stabilizing wire, according to an exemplary embodiment.

FIGS. 2-5 illustrate cross-sectional views of various exemplaryembodiments of a multichannel cannula.

FIG. 6 illustrates a multichannel cannula having a side port and adelivery portal, according to an exemplary embodiment.

FIG. 7 illustrates a multichannel cannula with a plurality of exitportals, including open distal ends of channels and multiple side ports,according to an exemplary embodiment.

FIG. 8 illustrates the bone and stabilizing wire shown in FIG. 1 with amultichannel cannula introduced over the stabilizing wire, according toan exemplary embodiment.

FIG. 9 illustrates a multichannel cannula with a stabilizing wire withina first channel and a delivery insert within a second channel.

FIG. 10 illustrates a cross-sectional view of an exemplary embodiment ofa multichannel cannula.

FIG. 11 illustrates a longitudinal section view of an exemplaryembodiment of a multichannel cannula with a distal tip and a cap.

FIG. 12 illustrates the multichannel cannula and cap shown in FIG. 11.

FIG. 13 illustrates the positioning of the cap along the multichannelcannula.

FIG. 14 illustrates the positioning of a plunger within a second channelof the multichannel cannula.

FIG. 15 illustrates a longitudinal section view of an exemplaryembodiment of a multichannel cannula with a distal tip and a cap.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplaryembodiments in detail, it should be understood that the application isnot limited to the details or methodology set forth in the descriptionor illustrated in the figures. It should also be understood that theterminology is for the purpose of description only and should not beregarded as limiting. For example, a femur is illustrated in thedrawings, but the devices and methods described herein may be used inconnection with any bone in the body, including but not limited to bonesin the spine, arms, hands, legs, and feet.

Referring to FIG. 1, a bone 10 includes a fracture 2. The fracture 2separates the bone into portions 10A and 10B. In surgical procedures torepair fractured bones, a stabilizing wire 4 may be used to hold boneportions together. The stabilizing wire 4 may be any type of wire usedto temporarily or permanently secure portions of bone together, such asKirschner wires or Steinmann pins. The stabilizing wire 4 is oftenplaced in a fractured bone 10 prior to insertion of a more permanentbone implant, such as a bone screw, nail, or other fixation structure.In addition to stabilizing the bone portions 10A and 10B, thestabilizing wire 4 may serve as a guide for a drill or bone implant. Forexample, the bone 10 of FIG. 1 includes a hole 6 created to eventuallyreceive a bone implant. To create the hole 6, a cannulated drill orreamer can be used to create a hole around the stabilizing wire 4 whilethe tip of the stabilizing wire 4 remains fixed in bone portion 10B. Thehole 6 passes through the fracture 2. A bone implant to further securebone portions 10A and 10B together can then be guided over stabilizingwire 4 and into the hole 6.

Referring to FIG. 8, according to an exemplary embodiment, amultichannel cannula 800 having two or more channels may be introducedover the stabilizing wire 4 to deliver substances to the interior ofbone 10. In one embodiment, the multichannel cannula is introduced overthe stabilizing wire 4 after creation of hole 6, but prior to placementof a bone implant into the hole 6. A first channel of the multichannelcannula receives the stabilizing wire 4. The other channels of themultichannel cannula may be used for delivering substances to theinterior of bone 10, as described in more detail below. The substancedelivered using the multichannel cannulas described herein may be anytype of substance a user desires to deliver to the interior of a bone,including growth factors or medication such as calcium phosphate paste,an antibiotic, pain medication, or a chemotherapeutic agent.

The multichannel cannulas described herein are substantially elongatedstructures with two or more channels, as can be seen in FIGS. 6-8 and 11(reference numbers 600, 700, 800, and 1100 respectively). Themultichannel cannulas described herein include a first channel (e.g.,801 shown in FIG. 8). having an open proximal end (e.g., 824 shown inFIG. 8) and an open distal end (e.g., 822 shown in FIG. 8). The openproximal end and open distal end allow the first channel to be threadedover a stabilizing wire 4. Thus, the first channel is configured toreceive a stabilizing wire 4. In one embodiment, the first channel issubstantially cylindrical and has a diameter slightly larger than thediameter of the stabilizing wire. The side wall of the cylindrical firstchannel (as distinguished from the open ends of the first channel) maybe continuous, meaning there are no open portals or other openings alongthe side wall of the first channel. In one embodiment, liquid cannotpenetrate the side wall of the first channel.

The multichannel cannulas described herein further include a secondchannel (e.g., 802 shown in FIG. 8). The second channel includes atleast one inlet portal (e.g., 820 shown in FIG. 8) and at least one exitportal (e.g., open distal end 810 shown in FIG. 8; side exit portals 708shown in FIG. 7). In some methods described herein, the inlet portal ofthe second channel serves as an inlet for a substance to be delivered tothe interior of a bone. In these embodiments, the exit portal of thesecond channel serves as an outlet for the substance. In other methodsof using a multichannel cannula, the exit portal of the second channelserves as an inlet for material being drawn into the second channel andremoved from the interior of a bone. In these embodiments, the inletportal of the second channel serves out an outlet for this removedmaterial. The inlet portal and exit portal of the second channel arethus in fluid communication to allow substances or materials to bedelivered to or removed from the interior of a bone.

FIGS. 2-5 and 10 illustrate cross-sectional views of various embodimentsof multichannel cannulas. The multichannel cannulas shown in FIGS. 2-5each include at least two interior channels. The channels of amultichannel cannula may be structured in a variety of ways to enhance auser's ability to precisely deliver a substance to an intended locationwithin a bone.

The multichannel cannula 200 shown in FIG. 2 includes a first channel201 and a second channel 202. In this embodiment, first channel 201 issmaller than second channel 202, and first channel 201 is containedwithin the bounds of second channel 202. The cross-section ofmultichannel cannula 200 is substantially circular. In one embodiment,channel 201 receives a stabilizing wire 4 during a surgical procedure.

The multichannel cannula 300 shown in FIG. 3 also includes twochannels—first channel 301 and second channel 302. In the embodiment ofFIG. 3, first channel 301 and second channel 302 have substantiallycircular cross-sections and have approximately the same diameter.Furthermore, first channel 301 and second channel 302 are arranged nextto each other such that the multichannel cannula 300 has a substantiallyovular cross-section. During use of the multichannel cannula 300 of FIG.3, either first channel 301 or second channel 302 may receive astabilizing wire 4.

Referring to FIG. 4, multichannel cannula 400 includes a first channel401, a second channel 402, and a third channel 403. The first channel401 has a substantially circular cross-section, while second channel 402and third channel 403 have crescent-shaped cross-sections. Secondchannel 402 and third channel 403 are arranged on either side of firstchannel 401 such that multichannel cannula 400 has a substantiallyovular cross-section. In one embodiment, first channel 401 receives astabilizing wire 4 during a surgical procedure.

Multichannel cannula 500, shown in FIG. 5, includes five separatechannels. The cross-section of first channel 501 is substantiallycircular. Second channel 502, third channel 503, fourth channel 504, andfifth channel 505 have crescent-shaped cross-sections and are arrangedaround first channel 501. The cross-sectional shape of multichannelcannula 500 is thus an irregular shape, as illustrated in FIG. 5. In oneembodiment, first channel 501 receives a stabilizing wire 4 during asurgical procedure.

Referring to FIG. 10, multichannel cannula 1000 includes two channels.In the embodiment of FIG. 10, first channel 1001 and second channel 1002have substantially circular cross-sections. First channel 1001 has asmaller diameter than second channel 1002, and first channel 1001 iscontained within the bounds of second channel 1002 and positioned suchthat first channel 1001 and second channel 1002 are coaxial. In oneembodiment, channel 1001 receives a stabilizing wire 4 during a surgicalprocedure.

The multichannel cannulas described herein can be made of any materialsuitable for placement into a bone without harmful effects on thepatient. In one embodiment, the multichannel cannula is made ofstainless steel or other type of metal. In another embodiment, themultichannel cannula is made of a rigid plastic, such aspolyethylketone, that cannot be easily bent or manipulated intoalternative configurations. A rigid cannula may be advantageous toprovide stability when introducing the cannula into a hole 6 in a bone10. Furthermore, a rigid cannula provides stability for variousprocedures that a more flexible multichannel cannula may not provide.For example, if a surgeon desires to use a plunger or other device topush a substance from the multichannel cannula and into the bone, arigid cannula may be more desirable. As another example, a rigid cannulais able to withstand more significant forces than a flexible cannula(e.g., forces applied to the cannula by a delivery device 628 or asuction device 826, and the forces resulting from movement of substancesthrough the channels and through any open portals in the cannula).

FIG. 6 provides a perspective view of another embodiment of amultichannel cannula. Multichannel cannula 600 includes a first channel601, a second channel 602, a delivery portal 604, and a side exit portal608. The multichannel cannula 600 is threaded over a stabilizing wire 4,such as stabilizing wire 4 in bone 10 (as shown in FIG. 8). Thestabilizing wire therefore lies within the first channel 601. Thedelivery portal 604 is coupled to an inlet portal 620 of the secondchannel 602 such that a substance can flow from the delivery portal 604,through the inlet portal 620, and into the second channel 602. Thedelivery portal 604 may be angled relative to the multichannel cannula600, as shown in FIG. 6. In an alternative embodiment, the longitudinalaxis of the delivery portal 604 is aligned parallel to the longitudinalaxis of the multichannel cannula 600.

Various delivery devices can be coupled to the delivery portal 604 toassist in delivering substances to the second channel 602 ofmultichannel cannula 600. The delivery portal 604 may include aremovable plug 606. In one embodiment, a user removes plug 606 to couplea delivery device 628 (illustrated schematically in FIG. 6) to deliveryportal 604. The delivery device 628 may include a syringe, a pump, or areservoir. Tubing 629 may be used to connect the delivery device 628 tothe delivery portal 604. The type of delivery device selected by a usermay depend on the type of substance to be delivered to the bone.

Once a substance has been delivered to second channel 602 of themultichannel cannula 600 through the inlet portal 620, the substanceexits second channel 602 via a side exit portal 608 located on an outerwall of the second channel 602. In this embodiment, the distal end 610of second channel 602 is closed, preventing the substance from exitingthe distal end 610 of the second channel 602. However, in an alternativeembodiment, the distal end 610 of the second channel 602 may be open tocreate an exit portal such that the substance can exit the secondchannel 602 through both the side exit portal 608 and the open distalend 610. During use of multichannel cannula 600, a user can align theside exit portal 608 with the area of the bone to be treated with thesubstance.

Referring to FIG. 7, multichannel cannula 700 includes five channels(701-705), each with an open distal end that can serve as an exit portalfor substance delivery. In this embodiment, the fourth channel 704includes a plurality of side exit portals 708, although any of the otherchannels 702-705 may include one or more side exit portals. The firstchannel 701 is configured to receive stabilizing wire 4 during asurgical procedure. A substance can be delivered to the inlet portals ofany of channels 702-705 via a delivery portal, such as the deliveryportal 604 described in connection with FIG. 6. In one embodiment, thesubstance is delivered to fourth channel 704. The substance then travelsthrough fourth channel 704, exiting through side exit portals 708 andthe exit portal created by the open distal end 710 of the fourth channel704. In an alternative embodiment, the distal end 710 of fourth channel704 is closed to prevent substance from exiting the distal end 710. Themultiple exit portals 708, 710 in the embodiment of FIG. 7 allow thesubstance to be delivered to multiple areas within the interior of abone. For example, the open distal end 710 may deliver the substance toa distal end of a hole 6 in a bone (e.g., in bone 10 shown in FIG. 8)while the exit portals 708 deliver the substance to one or more fracturesites 2.

FIG. 11 provides a cross-section view of another embodiment of amultichannel cannula. Multichannel cannula 1100 includes a first channel1101, a second channel 1102, and side exit portals 1109. Themultichannel cannula 1100 is threaded over a stabilizing wire 4, such asstabilizing wire 4 in bone 10 (as shown in FIG. 8). The stabilizing wiretherefore lies within the first channel 1101. The distal end of cannula1100 may include a distal tip 1103. As shown, the distal tip 1103 mayinclude a tapered portion 1104 extending from the distal end of thecannula 1100. An engagement portion 1105 is coupled to the distal endsof the first channel 1101 and the second channel 1102. In the embodimentshown, the engagement portion may be configured to fit between the sidewall of the first channel 1101 and the second channel 1102. The distaltip 1103 further includes a channel 1106 for receiving a portion of thestabilizing wire 4 therethrough.

As shown in FIGS. 11 and 12, multichannel cannula 1100 may also includea cap 1120. The cap 1120 has a housing portion with a channel forcoupling to a portion of the proximal end of cannula 1100. The channelof the cap 1120 may extend from first end through a second end of thehousing portion for receiving the stabilizing wire 4 therethrough. In apreferred embodiment, the cap 1120 is affixed to the multichannelcannula 1100, such as during production of the cannula 1100. In analternative embodiment, the cap 1120 may be removable. The cap 1120 maybe positioned at the site of the hole in the bone, such as hole 6 asshown in FIG. 8, in order to serve as a plug. In this way, cap 1120plugs the hole 6 and may prevent irrigation or other substance beingdelivered to the site from coming back up through the hole 6 in thebone. In another embodiment, a separate temporary plug or seal may beadded to the cannula to plug the hole 6 in the bone. In the embodimentshown, cap 1120 also has a delivery portal 1122. The delivery portal1122 is coupled to an inlet portal of the second channel 1102 such thata substance can flow from the delivery portal 1122, through the inletportal, and into the second channel 1102. As described in connectionwith FIG. 6, various delivery devices can be coupled to the deliveryportal 1122 to assist in delivering substances to the second channel1102 of multichannel cannula 1100. The delivery portal 1122 may includea removable plug 1123. The delivery device may include a syringe, apump, or a reservoir. Tubing may be used to connect the delivery deviceto the delivery portal 1122.

Once a substance has been delivered to second channel 1102 of themultichannel cannula 1100 through the inlet portal, the substance exitssecond channel 1102 via a side exit portal 1109 located on an outer wallof the second channel 1102. During use of multichannel cannula 1100, auser can align the side exit portal 1109 with the area of the bone to betreated with the substance. In an alternative use, the desired locationof the side portal 1109 can be determined at the time of the procedure,including after the stabilizing wire has been inserted and the hole inthe bone has been created, to determine the preferred site of substancedelivery. Thus, once the desired location is determined, the side portal1109 can be created in the outer wall of the second channel 1102, or inanother location on the multichannel cannula 1100 from which thesubstance can be delivered to the target site in the bone.

As shown in FIG. 13, an embodiment of the cap 1120 has a flange 1127 toprovide improved gripping capability for positioning the cap 1120, ifnecessary. In some embodiments, the cap 1120 may be removed in order toaccommodate the passage of a plunger 1130, such as the plunger 1130shown in FIGS. 14 and 15. FIG. 14 depicts the plunger 1130 being used toassist with delivery of a substance through an exit portal, such as exitportal 1109. The plunger 1130 is configured to pass through themultichannel cannula 1100 in the second channel 1102 after a substancehas been introduced into the channel 1102 through the inlet portal. Asshown in FIG. 15, the cap 1120 and the plunger 1130 may be configured toengage such that a distal portion of the plunger 1130 is received in andengages with the channel of the cap 1120. In this embodiment, the cap1120 may be affixed to the cannula 1100 or may be removable. The plunger1130 fits around the first channel 1101 and may have a distal endconfigured to fit in the channel of the cap 1120 and capable of beingmoved within the second channel 1102 of the cannula 1100.

In an alternative embodiment, the second channel 1102 may have a distalopening into the first channel 1101. In this embodiment, the firstchannel 1101 may have a distal opening for the stabilizing wire 4 and aside opening 1109 for the substance to exit to the bone. The plunger1130 in this embodiment would be configured to move within the firstchannel 1101, over the stabilizing wire 4, to deliver the remainingmaterial to the desired area.

FIG. 8 illustrates a multichannel cannula 800 placed within bone 10 forsubstance delivery. The multichannel cannula 800 illustrated in FIG. 8includes at least a first channel 801 and a second channel 802. Firstchannel 801 is shown threaded over stabilizing wire 4. Second channel802 is therefore used for substance delivery or to remove material fromthe interior of a bone. In the embodiment shown, the second channel 802includes one or more expandable portions 830. The expandable portions830 may be balloons configured to expand between the outside of thecannula 800 and the sidewall of the hole 6 formed in the bone. Theexpandable portions may provide stabilization to the cannula inserted inthe bone and/or may provide a mechanism to isolate certain areas of thebone for delivery of the substance via the cannula 800. For example, afirst expandable portion 830 may be positioned below an exit portal andanother expandable portion 830 positioned above the exit portal, suchthat substance delivered through the exit portal is only delivered tothe portion of the bone between the two expandable portions 830. Inanother example, the expandable portions 830 may provide temporarystabilization of the cannula when extended medication delivery is needed(such as several hours or days). In this way, medication may bedelivered over an extended period of time prior to, as an example,placement of an implant. Any of the embodiments of multichannel cannulasdescribed herein (e.g., 200, 300, 400, 500, 600, 700, 800, 900, 1000,and 1100), and any combination of the features of these embodiments, maybe utilized in the manner shown in FIG. 8 to either deliver a substanceto bone or remove material from the interior of a bone. Thus, referencesand disclosures related to methods for using multichannel cannula 800are to be understood to be references and disclosures related to methodsfor using any of the other structural embodiments of multichannelcannulas described herein.

One method of delivering a substance to bone according to an exemplaryembodiment includes placing stabilizing wire 4 into bone 10 and creatinga hole 6 in the bone 10 around the stabilizing wire 4, as describedabove. The method further includes providing a multichannel cannula 800having a first channel 801 with an open proximal end 824 and an opendistal end 822. As also described above, the proximal end 824 and distalend 822 of the first channel 801 are open so that the first channel 801can receive the stabilizing wire 4. The multichannel cannula 800 furtherincludes a second channel 802 having an inlet portal 820 and an exitportal 818 that are in fluid communication.

The multichannel cannula 800 may be inserted into the hole 6 in the bone10 such that the first channel 801 receives the stabilizing wire 4.During the step of inserting the multichannel cannula 800 into the hole6, the multichannel cannula 800 can be inserted into the proximal end 6Aof hole 6 to any desired depth. The expandable portions 830 may beinserted into the hole 6 in a deflated state. When the cannula 800 is inplace, and the exit portal 818 is at the desired position, theexpandable portions 830 may be inflated. The inflated expandableportions 830 may provide stabilization of the cannula 800 at the desiredlocation. A substance is then delivered to the interior of bone 10 byintroducing the substance into the inlet portal 820 of the secondchannel 802 such that the substance exits the second channel 802 throughthe exit portal 818 (i.e., the open distal end 810 of second channel802). In one embodiment, the multichannel cannula 800 is inserted intohole 6 such that the distal end 809 of the multichannel cannula 800 isnear fracture 2. The substance can therefore be delivered to thefracture site through the open distal end 810 of the second channel 802.In another embodiment, the multichannel cannula 800 is inserted fartherinto hole 6 such that substance is delivered through the open distal end810 of the second channel 802 closer to the distal end 6B of hole 6. Inan embodiment having side exit portals, such as the side exit portals1109 in FIG. 11, the expandable portions 830 may also serve to isolatecertain areas of the bone, such as the area near fracture 2, so that thedelivered substance is focused at the desired area.

A user may select a multichannel cannula having a particularconfiguration and number of exit portals depending on a patient's bonefracture. For example, some types of fractures may be most easilytreated by delivering a substance to a location that can be aligned witha distal end of a multichannel cannula. In this scenario, a user mayselect a multichannel cannula 800 in which the distal end 810 of asecond channel 802 is open such that the substance can be delivered tobone 10 through this open distal end 810. In connection with other typesof fractures, the user may desire to treat the bone 10 by deliveringmedication to one or more locations along the periphery of a hole 6 inthe bone 10. Thus, a user may select a multichannel cannula 800 in whichdistal end 810 of second channel 802 is closed, and a substance isdelivered to the bone through side exit portals such as those describedin connection with FIGS. 6 and 7. In yet another embodiment, a substancemay be delivered to bone 10 through a channel in multichannel cannula800 having both an open distal end 810 and one or more side exitportals.

The multichannel cannula 800 may also be used during treatment of apatient with a weakened, but unfractured bone. A patient's bone can beweakened due to osteoporosis, metastasis of a cancer, or other diseasethat causes bone deterioration. A surgeon may be able to analyze thestate of the patient's bone and determine areas that are likely tosustain a fracture in the future. To treat the weakened bone, astabilizing pin 4 is inserted and a hole is drilled into the bone. Themultichannel cannula 800 is then threaded over the stabilizing pin 4. Acement (e.g., calcium phosphate paste, methylmethacrylate) is injectedthrough a channel of the multichannel cannula 800. The cement penetratesthe surrounding bone and strengthens the area. After removal of themultichannel cannula 800, the hole in the bone may be filled with cementor a bone implant.

Prior to or during substance delivery, a user may rotate themultichannel cannula 800 around the stabilizing wire 4. Rotating themultichannel cannula 800 may help a user align an exit portal with anintended delivery location within the bone in order to direct substancedelivery to the intended delivery location. Furthermore, the ability torotate the multichannel cannula 800 around a stabilizing wire 4 may helpduring guidance of the multichannel cannula 800 proximally and distallywithin hole 6.

In addition to being useful for substance delivery to the bone, themultichannel cannula as described herein may be used in accuratepositioning of implants made of absorbable materials and includingreservoirs containing medications or other substances. The cannula mayalso be used for passage of debriding tools or imaging devices that areused during the surgical procedure.

Fluoroscopic guidance may increase a user's ability to precisely delivera substance to a desired location within bone 10. The ability to viewthe multichannel cannula 800 during insertion allows a user to adjustthe position of multichannel cannula 800 to precisely align any exitportals of the multichannel cannula 800 with the intended delivery siteswithin bone 10. Once the multichannel cannula 800 is positioned andsubstance delivery has begun, the user can use fluoroscopic guidance todetermine whether any adjustments to the position of the multichannelcannula 800 should be made to more precisely deliver the substance. Forexample, based on fluoroscopic guidance, the user may determine that themultichannel cannula 800 should be inserted farther into hole 6. Asanother example, the image guidance may indicate that multichannelcannula 800 should be rotated about stabilizing wire 4 to increasedelivery accuracy.

The multichannel cannulas described herein may include radiopaquemarkers to facilitate image guidance. The radiopaque markers may belocated on or near the distal tip of the multichannel cannula. In oneembodiment, separate radiopaque markers are provided near the distalopening of multiple channels of the multichannel cannula. Radiopaquemarkers may also be provided near side portal openings in the cannula.The radiopaque markers assist a user in accurately positioning themultichannel cannula during a surgical procedure to deliver or remove asubstance from a bone. Furthermore, the markers allow a user to seewhere a substance is exiting or entering the multichannel cannula.

Referring to FIG. 9, a multichannel cannula 900 in accordance withanother exemplary embodiment includes a first channel 901 and a secondchannel 902. The second channel 902 includes a side exit portal 908 forthe substance to exit the second channel 902. In the embodiment of FIG.9, an insert 912 having an exit portal 914 is used in combination withmultichannel cannula 900 to deliver a substance to bone. In analternative embodiment, the insert 912 includes multiple side exitportals (not shown). The insert 912 may be one of the embodiments ofinserts described in U.S. patent application Ser. No. 13/270,072, titled“Method and Device for Delivering Medicine to Bone,” filed Oct. 10,2011, and hereby incorporated by reference herein in its entirety. Inuse, the insert 912 is inserted into the second channel 902. A substanceis then introduced into the proximal end 916 of the insert 912. Thesubstance then exits the exit portal 914 of the insert and the exitportal 908 of the second channel 902 of the multichannel cannula 900.The insert 912 can be adjusted within second channel 902 to alter theamount of substance ultimately delivered through side exit portal 908 ofthe multichannel cannula 900. For example, the insert 912 may be pulledin a proximal direction (i.e., away from the multichannel cannula 900)such that only a portion of side exit portal 914 is aligned with sideexit portal 908. Alternatively, the insert 912 can be pushed in a distaldirection to fully align side exit portal 914 with side exit portal 908,as shown in FIG. 9, which maximizes the amount of the substancedelivered through side exit portal 908. The insert 912 may also berotated around its longitudinal axis to alter the alignment of side exitportal 914 of the insert 912 and side exit portal 908 of themultichannel cannula 900, thus adjusting the amount of the substancedelivered. A delivery device 628 (shown schematically in FIG. 6), suchas a syringe, a pump, or a reservoir, may be attached to the proximalend 916 of the insert 912.

In another exemplary method, any of the multichannel cannulas describedherein may be used to remove material, such as bone marrow or blood,from the interior of a bone 10. Referring to FIG. 8, a suction device826 may be coupled to the proximal end of multichannel cannula 800 toaid in the removal of material. In one embodiment, the suction device826 is coupled to the proximal end of second channel 802 by tubing 829or via a delivery portal (e.g., the delivery portal 604 shown in FIG.6). Upon activating the suction device 826, material being removed fromthe bone 10 travels through the multichannel cannula 800 in an oppositemanner from the embodiments in which a substance is being delivered tothe bone through multichannel cannula 800. For example, in theembodiment shown in FIG. 8, activation of suction device 826 causesmaterial to enter the multichannel cannula 800 through the exit portalcreated by open distal end 810 or through any side exit portals in themultichannel cannula 800. The material then travels through secondchannel 802 and exits the multichannel cannula 800 through the inletportal 820 at the proximal end of the second channel 802. The exitportals of the multichannel cannula 800 may be aligned within bone 10 toremove material from intended locations near the exit portals.

A user may use the multichannel cannula 800 to both deliver substancesto bone 10 and remove materials from the interior of a bone 10 duringthe same surgical procedure. In one embodiment, a user first uses themultichannel cannula 800 to remove material from the interior of thebone 10. Next, the multichannel cannula 800 is used to deliversubstances to areas within the bone 10. Alternatively, a user may firstdeliver a substance to the interior of bone 10 using the multichannelcannula 800. After substance delivery, the user may remove excesssubstance (e.g., medication) or other materials (e.g., blood) byutilizing a suction device 826 coupled to the proximal end of themultichannel cannula 800. The combination of a multichannel cannula andan insert, such as the multichannel cannula 900 and insert 912 shown inFIG. 9, may similarly be used in connection with a suction device 826 toremove material from the interior of a bone 10. In this embodiment, thesuction device 826 can be coupled via tubing or via a delivery portal(e.g., the delivery portal 604 shown in FIG. 6) to the proximal end 916of the insert 912.

The multichannel cannulas described herein can be used to irrigate theinterior of a bone by simultaneously delivering a substance to the bone10 using one channel and applying a suction force to a separate channel.Irrigation may be useful for reducing the risk of infection orcontamination within a bone. In one embodiment, a solution containingantibiotics or other medication is introduced into a first channel of amultichannel cannula. The solution travels through the first channel andenters the interior of a bone through one or more exit portals of thefirst channel. Simultaneously or shortly thereafter, a suction force isapplied to a second channel of the multichannel cannula using a suctiondevice, such as suction device 826 shown in FIG. 8. The suction drawsthe solution from the interior of the bone and back into themultichannel cannula through an open portal of the second channel. Inthis manner, the interior of the bone can be irrigated using amultichannel cannula. The channel used to deliver the substance to thebone may or may not contain a stabilizing wire 4. Similarly, the channelused to draw the substance back out of the bone may or may not contain astabilizing wire 4. In other words, the presence of a stabilizing wire 4within a channel does not prevent substances from flowing through thechannel.

The various multichannel cannula embodiments can be used in surgicalprocedures other than in connection with delivering or removingsubstances from bone. For example, the multichannel cannulas can be usedin procedures requiring insertion of a cannula into a vessel. In thisembodiment, a guidewire is inserted into the patient's vessel, and afirst channel of the multichannel cannula is then threaded over theguidewire. The cannula can then be used as described in connection withthe various methods disclosed herein to deliver or remove a substancefrom the vessel through a channel of the cannula. In another embodiment,the multichannel cannula is used in ear, nose, and throat procedures,with or without the use of a guidewire.

The construction and arrangement of the devices and methods as shown inthe various exemplary embodiments are illustrative only. Although only afew embodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, use ofmaterials, orientations, etc.). For example, the position of elementsmay be reversed or otherwise varied and the nature or number of discreteelements or positions may be altered or varied. Accordingly, all suchmodifications are intended to be included within the scope of thepresent disclosure. The order or sequence of any process or method stepsmay be varied or re-sequenced according to alternative embodiments.Other substitutions, modifications, changes, and omissions may be madein the design, operating conditions and arrangement of the exemplaryembodiments without departing from the scope of the present disclosure.

What is claimed is:
 1. A method of delivering a substance to a bone,comprising: placing a stabilizing wire in a bone; creating a hole in thebone around the stabilizing wire; providing a multichannel cannulacomprising: a first channel having an open proximal end and an opendistal end, wherein the first channel is configured to receive astabilizing wire; and a second channel having an inlet portal and anexit portal, wherein the inlet portal and the exit portal are in fluidcommunication for continuous flow of the substance from the inlet portalto the exit portal; a distal tip at a distal end of the cannula, the tipcomprising a tapered portion and an engagement portion, and having achannel extending therethrough for receiving a portion of thestabilizing wire; wherein the engagement portion of the distal tipcomprises a portion having a smaller diameter than an inner diameter ofthe second channel such that the engagement portion can be receivedwithin the second channel and wherein the engagement portion is coupledto the first channel; and inserting the multichannel cannula into thehole in the bone such that the first channel receives the stabilizingwire; delivering the substance into the bone by introducing thesubstance into the inlet portal of the second channel such that thesubstance flows continuously in the second channel between the inletportal and the exit portal, wherein the stabilizing wire remains placedin the bone and received by the first channel during delivery of thesubstance to the bone.
 2. The method of claim 1, further comprising:positioning a cap on the multichannel cannula, wherein the cap comprisesa channel for receiving a portion of the cannula therein, and furthercomprises a delivery port; wherein positioning the cap further comprisespositioning the cap such that the delivery port is in fluidcommunication with the inlet portal of the second channel.
 3. The methodof claim 2, wherein the delivery port extends at an angle relative to alongitudinal axis of the cannula.
 4. The method of claim 2, whereinpositioning the cap further comprises positioning the cap such that thecap closes at least a portion of the inlet portal.
 5. The method ofclaim 1, further comprising determining a desired location of the exitportal in an outer wall of the second channel and creating the exitportal in the outer wall at time of surgical procedure.
 6. The method ofclaim 1, further comprising positioning a plunger about the firstchannel and between the first channel and the second channel so as toassist in the delivering of the substance from the cannula to the bone.7. The method of claim 6, further comprising moving the plunger betweena first position and a second position within the second channel todeliver the substance from the cannula.
 8. The method of claim 6,further comprising positioning a cap on the multichannel cannula overthe cannula and a portion of the plunger.
 9. The method of claim 1,wherein the multichannel cannula further comprises an expandable portiondisposed around a portion of the length of the cannula, wherein theexpandable portion is configured to expand to form a contact between thecannula and the surrounding bone when inserted into an aperture in thebone.
 10. The method of claim 9, further comprising isolating area ofbone by expanding the expandable portion to create a seal between themultichannel cannula and the surrounding bone.
 11. The method of claim9, further comprising securing the multichannel cannula in position inthe aperture in the bone by expanding the expandable portion to contactthe surrounding bone.
 12. The method of claim 1, further comprisingintroducing through the cannula an implant made of an absorbablematerial and comprising a substance reservoir to the bone.
 13. Themethod of claim 1, further comprising introducing through the cannula atleast one of a debriding tool and an imaging device to an area of thebone being treated.